Earthquake protected building construction



March 24, 1936. G, VA L ER 2,035,143

EARTHQUAKE PROTECTED BUILDING CONSTRUCTION Filed July 29, 1955 sShets-Sheet 1 Q 'N' w 8% N March 24, 1936. CAVAGUER! 2,035,143

EARTHQUAKE PROTECTEI) BUILDING CONSTRUCTION Filed July 29, 1955 5Sheets-Sheet 2 March 24, 1936. e, CAYAGLIERI EARTHQUAKE PROTECTEDBUILDING CONSTRUCTION Filed July 29, 1935 3 Sheets-Sheet 3 v PatentedMar. 24, 1936 mm STATES EARTHQUAKE PROTECTED BUILDING CONSTRUCTIONGiuseppe Cavaglieri, Los Angeles, Calif., assignor to Grace F. Marquis,Los Angeles, Calif.

Application July 29, 1935, Serial No. 33,644

9 Claims.

This invention is directed generally to the provision ofearthquake-protected building structures.

The so-called rigid type of building has previously been generallyaccepted as offering the greatest security against damage fromearthquake shocks. However, earthquake movements caused in buildings ofthe rigid type are often of considerable magnitude and while suchbuildings as ordinarily constructed may be in no substantial danger ofcomplete collapse from earthquakes even of relatively great severity,the relative bending, shearing and twisting movements set up in theirvarious members frequently result in considerable damage being done towalls, plaster, piping, etc. Moreover, buildings of the rigid typedesigned to withstand earth shocks are relatively expensive to erect.

It is a general object of the present invention to provide a novel typeof building in which movements caused by earthquakes are practicallyeliminated.

My invention accomplishes this object through the provision of what maybe generally described as a flexible horizontal plane or planes betweenthe foundation and the superstructure of the building, the foundation,below this plane, being capable of moving horizontally beneath thesuperstructure with movement of the earth,

while the superstructure remains nearly stationary in position. Theflexible plane between the foundation and the superstructure consists ofa series of ball and cup assemblies, which are so arranged as to allow alimited relative hori- 5 zontal movement of the foundation below thesuperstructure by a rolling action on these balls. The halls are set,top and bottom, on concave bearing surfaces secured to thesuperstructure and foundation, respectively, so that a quick horizontalmovement of the foundation due to an earthquake shock will cause theballs to roll up slightly inclined bearing surfaces, thus slightlylifting the superstructure. If the shock is of a vibratory character,the balls roll back and forth across the concave bearing surfaces,alternately slightly lifting and then lowering the superstructure, andfinally settling to the centers of the bearing surfaces upon completionof the earth movements. The rolling action between the foundation andsuperstructure absorbs a great quantity of the energy of the shock, andthe great inertia of the superstructure prevents it from receivingsubstantial movement as the foundation shifts in horizontal directionswith the earthquake. Of course, due to the reaction of the ball supportsas the foundation is moved by the earth shock, the building will havesome small movement in a direction opposite to that of the earth shock,but this movement will be comparatively small because of the great mamof the building. It is estimated that earth vibrations arising fromearthquakes do not measure over from to /8" in amplitude-where theground is solid, or over approximately one inch in soft or muddy soil.Due to reaction, the building of the present invention may then have anopposing vibratory movement of say A," amplitude, this of coursedepending upon its mass and inertia. Such a reduction in motion ishighlyv beneficial, and reduces the effect of a very severe earthquaketo an effect comparable with that experienced in ordinary buildings withvery light earth movements.

A further feature of the invention is the provision of a modifiedcontour on the concave surfaces of the ball-supporting cups, designed toprevent the superstructure from moving at increasing amplitude in timedstep with the vibratory motion of the earth in the event the period ofthe earth movement should for a time equal the natural period ofvibration of the superstructure. It is of course improbable that theperiod of vibration of an earthquake would match the natural period ofthe superstructure, but if such should occur, severe movement of thesuperstructure might result. I eliminate possibility of such action byforming, the concave bearing surfaces with slight, circular, wave-likedepressions, which have the effect of breaking up entirely any tendencyof the superstructure to time with vibration of the earth.

The invention will be more fully understood from the following detaileddescription of a present preferred embodiment thereof, reference forthis purpose being had to the accompanying drawings, in which:

Fig. 1 is a horizontal section of a. building showing portions of thepresent invention;

Fig. 2 is a vertical section taken on line 2-2 of .1;

Fig. 3 is an enlarged view of a portion of Fig. 2;

Fig. 4 is a detail section showing typical flexible pipe connectionsadapted for the building of the present invention; and

Fig. 5 is a detail section of a. bearing cup having a modified contour;

Fig. 6 is a face view of one of the bearing cups; and

Fig. 7 indicates a flood type of foundation enthe concrete (Fig. 2).

tirely covered semblies.

Fig, 1 is a plan section of an illustrative buildwith I beams ca yinball asing incorporating the present invention. This with suitablereenforcing iron, as at I9 and l9a,

though the invention is applicable to a building having any usual orapproved type of construction.

The foundation is designated by numeral 20, and is understood to becarried by any usual earth supported footing, not shown. The upper sideof the foundation is furnished with fiat surfaces 22 which serve asplatforms for longitudinally arranged I-beams 24 which carry ballassemblies on which the super-structure is rested. The number andarrangement. of these I-beams and ball assemblies depends upon theconfiguration 0f the foundation and the weight to be, carried by it. Inthe case of a single storygauilding, a single I-beam running aroundthe-upper side of the foundation is usually sufficient, and for thesingle story part of the building illustrated in Fig. 1, a single I-beamis used on each foundation wall.

At each of the two corners of the foundation which underlie columns I3and I4, however, a short-length I-beam 25 is employed alongside the endof one of the main I-beamstogive additional weight carrying capacity,the foundation wall being made of sufiicient size to accommodate theextra I-beam, all as clearly illustrated in Figs. 1 and 2. For the twostory part of the building of Fig.1, the foundation is shown as made ofdouble width, and a second Ibeam is laid parallel to the first. It willbe obvious that as many I- beams may be employed as is necessary for theweight to be carried, and these may be laid as good design dictates.Fig. I shows how, where form type, foundation 28 may be employed, and

may be entirely covered with I-beams 24, arranged as indicated, andwelded together at the ends. The junctures of the I-beams, at thecorners of the building, or at any angles in the foundation, are weldedtogether, as along the line designated at 26 in Fig. 1. Also, atcriticalplaces, steel ties 0r struts. are welded between the 1- beams,as typically indicated at 21 in Figs. 1 and 2. These I-beams 24 aresecured to the foundation by means of a suitable number of anchor bolts30, which are embedded at their lower ends in the concrete foundation,and have screwthreaded upper ends extending up throughholesin the websof the I-beams, nuts 3! being screwed on the upper ends of the anchorbolts and set down against the I-beam webs The I-beams are preferablyfurther braced by setting their lower flanges 33 down into The uppersurface of the foundation walls are thus provided with a continuoussteel I-beam tie, made fast to and braced by the concrete foundation.The foundation is also braced diagonally in a horizontal plane, as bydiagonal ties such as indicated at 28, anchored at their ends into theconcrete.

Secured in similar manner to the undersides of bearing walls I8, whichare also braced diagonally,

as by ties 29 anchored at their ends in the walls, and of all supportingcolumns of the superstructure, are upper I-beams 40, one being arrangedover and parallel to each foundation I-beam 24. As clearly shown, theupper Ibeams are of greater width than the lower I-beams 24, and thedepending flanges 4! of the upper beams receive between them theupstanding flanges 42 of the lower beams. The upstanding flanges 44 ofupper beam 40 preferably are set into the concrete bearing walls l8, andthe webs of beams 40 are secured to said walls by means of embeddedanchor bolts 45 and nuts 46. The flanges of the upper I-beams preferablyengage one another, wherever two are used side by side, and may befastened together as by welding.

If desired, the interior angles between adjacent walls of thesuperstructure, and also the foundation, may be additionally braced byuse of knee braces such as indicated at 31 in Fig. 1, such braces beinganchored to the walls as by anchors 38. In some cases such knee bracesmay be used without the diagonal'ties, if desired.

Ball and cup assemblies 50 are placed between the webs of the upper andlower I-beams, and

carry the entire load of the superstructure. These respectively,providing concave seats 53 for hard steel balls 54. These balls 54 carrythe weight of a high factor of safety against crushing. They maytypically be from 1 1 to 3" in diameter, although this suggestion is notto be taken as limitative on the invention. The radius of curvature of'theconcave seating surfaces 53 is considerably greater than that of theballs, as indicated. Since the curvature of these seats is subject to.rather wide possible variation, depending upon particular conditions tobe met, no typical curvature is here specified, beyond to note that therelative curvatures of the balls and their seats are preferablysubstantially as indicated in Fig. 3 of the drawings. It should bepointed out, however, that the balls should be of uniform diameter, andthe curvatures of all sets of bearings should likewise be uniform.However, while all concave bearing surfaces should be uniform with eachother, it may be advisable to form each concave bearing surface with awave, or ,annular depression, concentric with the center of the bearing.The exact nature of such modification of the bearing surface and thebenefit gained thereby will be explained hereinafter.

Bearing members 5| and 52 are furnished with rings 51, of an insidediameter substantially equal to the diameter of concave seating surfaces53. These rings 51 and the bearings themselves are rigidly secured tothe webs of the I-beams by means of bolts 58 and nuts 59. The purpose ofthese rings will appear hereinafter.

The ball and cup assemblies are so placed and distributed over theI-beams asto carry substantially equal loads, considering both the deadand probability-adjusted live loads of the buildof the building isfurnished with approximately ,double the number of balls provided forits one story, half.

The building of course stands normally with the balls centered on theconcave bearings. Upon horizontal motion of the earth arising from anearthquake, the foundation moves with the earth, while thesuperstructure, because of its great inertia, and because of theflexible plane" between it and the foundation, tends to hold toposition. The movement of the foundation relatively to thesuperstructure occurs by a rolling action on balls 56. There is ofcourse a reaction set up through the balls which tends to move thesuperstructure in a direction opposite to that of the earth andfoundation movement, and this may cause some movement of the building ina direction opposite to that of the earth shock, but such movement isvery small compared to the amplitude of movement of the earth andfoundation. As the foundation rolls beneath the superstructure, a largepart of the energy of the shock is absorbed in rolling resistance, whichof course depends upon the weight of the superstructure. Uniform loadingof the balls insures that each ball will absorb its share of energyduring this rolling action. Thus, as the foundation is relativelydisplaced by an earth shock from. its normal position of rest, the ballsroll on the foundation and superstructure bearings, the buildingremaining substantially stationary as regards horizontal movement, or'moving slightly in a direction contrary to that of the earth shockbecause of a reactive effect received from the balls. Because of theconcavity of the bearings supporting these balls, the building issimultaneously slightly elevated, and on completion of such adisplacement movement of the foundation, the weight of the buildingcauses the balls to return on the concave surfaces to centered position,realining the foundation and superstructure. An earthquake causes avibratory motion of the earth ranging up to A in amplitude for mostsevere conditions, assuming solid or substantially rigid groundconditions. Accordingly, the foundation is displaced first in onedirection and then in another with reference to its normal position ofrest, the balls climbing the inclined bearing surfaces to elevate thebuilding with each departure from centered position, and on completionof such movement, descending the bearing surfaces in a path eitherthrough center, or to one side of center, to'climb the bearing surfacesin another direction. The foundation will of course follow somewhat of arandom path, depending upon the characteristics of the earthquake, butthe action will be in the nature of a swing from side to side, thesuperstructure being alternately raised and lowered as the balls travelup and back down the concave bearings with movement of the foundationfirst away from and then back toward its normal position of rest. As thevibratory motion of the earth declines in amplitude, the movement of thefoundation below and relatively to the superstructure decreasesaccordingly, and the ball and cup bearing assemblies assure that thebuilding will finally settle back into its original position of rest,with the superstructure again square with the foundation. It will beseen that the overall effect of the ball and cup supporting assembliesis to absorb energy of the shock and to prevent its acceleration frombeing transmitted to the superstructure of the building.

The flexibility provided by the present invenor unforeseen movementsshould occur, the overlapped I-beam flanges 4i and 42 would finallyengage one another, and that thereafter further play will be afforded inbending of the flanges. This will allow some motion to be transmitted tothe superstructure, but even in such event, the building would bereasonably protected by reason of the fact that the shock would begreatly softened before the actual flange engagement could occur. It iscontemplated that for an ordinary or small building the upper I-beamsmay preferably be from three to four inches wider, from flange toflange, than the lower I-beams, so that the flanges will not engage inthe manner just described unless a movement should occur of from one andone-half to two inches amplitude. A high factor of safety is therebyafforded since, as noted hereinbefore, it has been estimated that anearthquake of the most severe character so far known would not cause avibratory earth movement of over substantially amplitude, or ofsubstantially 1" amplitude assuming loose or soft soil. However, aspreviously stated, if an earth movement of magnitude sufficient to causeengagement of the I-beam flanges should occur, further flexibility andplay is afforded in bending of the III-beam flanges, and reasonableprotection is therefore had even for extreme conditions far beyondforeseen limits. Preferably, the parts are so related that the ballswill strike the rings 5? simultaneously with such engagement of theflanges. These rings are preferably of some soft iron, as wrought iron,and the sharp comer of the washer engaged by the ball is mashed aroundwith any such engagement, so that there is no likelihood of cracking ofthe balls in meeting the rings. Instead, the balls simply mash a seatingsurface on the rings and tend to climb over them, and this action,together with bending of the then engaged I-beam flanges, absorbsfurther energy of the shock, as well as allowing overplayin the' eventof earth movements of unexpected magnitude. It has been stated that theupper I-beams may typically be from three to four inches wider, fromflange to flange, than the ports for the ball and cup assemblies, insome instances it may be desired to use channel beams in place ofI-beams. The present drawings are to be considered illustrative ofchannel as well as of lI-beams, it being noted that simple removal ofthe upstanding flanges of the upper I-beam and of the depending flangesof the lower I-beam converts the structure into channel form. The

channel form, in fact, is properly to be regarded as the generic form ofthe structure.'

It is conceivable, though improbable, that the period of vibration of anearth movement might time" with the natural period of thesuperstructure, in which event serious movement of the building mightoccur. Such action is effectively prevented,.however, by forming theconcave bearing surfaces as indicated in the enlarged and somewhatexaggerated views of Figs. 5 and 6. In said figures the upper and lowerconcave bearing surfaces are-again indicated at 53 and the ball isindicated at 54. In this instance, however, a shallow wave or annulargroove 51 is formed'in the face of each bearing surface. This groove ispreferably very shallow, being perhaps not over several thousandths ofan inch deep, though this it not to be taken as limitative on theinvention, and'is concentric with'thecenter of the concave bearing face.Any number of such concentric grooves may of course be employed, but oneis suflicient for the present illustration. This I groove absolutelyprevents the superstructure from timing with the vibratory motion of theearth, as it causes the ball travelling across it to be given a slighttendency for motion around the bearing, as well as to hesitate slightlyin crossing the groove, which at once breaks up any tendency for aperiodic response of the superstructure to the vibratory earth motion.As stated previously, it is considered only remotely possible that sucha periodic response of the superstructure might ever occur, but allpractical possibility of such action is removed by provision of thedescribed wave in the bearing surfaces, and this bearing formation maybe utilized if deemed desirable. Preferably, after assembly of theI-beam structure, the lower I-beam is filled to the top edge of theflanges with an oil of appropriate type, which provides, first. suitablelubrication for free action of the parts, and second, coverage toprevent corrosion. -At the ends of certain'of the I-beams, or wherevernecessary, oil confining plates 59 may be welded between the flanges(see Fig. l)

Supply pipes entering the building are provided with flexible or doubleswing joint connections which allow ample play in any direction. Ree

ferring to Fig. 4, in which the foundation is again indicated at and thesuperstructure side wall at l8, three utility pipe lines enter thesuperstructure indicated at 60, SI and 62. Line 60, which may beconsidered as a gas line, is shown provided with a flexible section 63,consisting simply of a series of bends or folds 64. Line 6|, which maybe a water supply pipe, has a flexible joint consisting of a pair ofspaced ball and socket joints 65 and telescopingpipe sections 66 and 61,provided with suitable packing. Line 62 may be a sewer pipe, and mayhave a flexible joint 69 just like that provided for line 6|. Thesefleidble connections afl'ord sufllcient play that the pipes will not bebroken with relative movement between the earth and superstructure,

In order to provide for overturning moment due to possible windpressures of unusual or normally unforeseen magnitude, or of earthquakeforces, a series of hold-down links Hi is' placed on the basement sideof the exterior foundation walls and connected with the superstructure.These links, formed with upper and lower eyes II, are connected top andbottom 'with anchors 13 and I4 embedded in bearing wall l8 andfoundation 20 respectively. Suflicient play is aflorded that the linkswill not tighten within the range of con- The provisions of the presentinvention absorb a large share of the energy of an earth shock, andreduce to negligible amount the movements transmi ted to thesuperstructure. The operability f the invention is notobviated in'theevent of settling of one end'of the building, the superstructure beingcapable of the necessary rolling andself-centering action relative tothe foundation, even though the foundation is at a considerable anglerelative to horizontal.

It'will be understood the drawings 'and description are to be consideredas illustrative or rather than restrictive on the broader claimsappended hereto,- since various changes in design, structure andarrangement may be made without departing from the spirit and scope ofsaid claims.

I claim:

1. In an earthquake protected building construction, the combination ofa foundation structure, a building superstructure over said foundationstructure, a set of balls distributed over the upper side of thefoundation structure and adapted to receive and carry the load of thesuperstructure and transmit it to the foundation, and upper and lowerconcave bearings for the top and undersides of each ball, saidbearingsbeing rigidly mounted on the underside of the superstructure and the topside of the foundation, respectively, and said concave bearing surfacesbeing circular in formation, of radii of curvature greater than that ofthe balls, and having secondary concentric circular depressions. 2. manearthquake protected building c onstruction, the combination of afoundationstructure, a building superstructure over said foundationstructure, an I-beam mounted on the top surface of the foundationstructure, with its web in a horizontal plane, a corresponding I-beammounted on the underside of the superstructure directly over andparallel to the foundation I-beam, and with its web in a horizontalplane, a plurality of upwardly facing concave bearings rigidly mountedon the upperside of the foundation I-beam web, a like plurality ofballs, of radius of curvature less than that of the bearings,

resting on said bearings, and a plurality of down-. wardly facingconcave bearings, of radius of curvature greater than that of the balls,rigidly mounted on the lower side of the superstructure directly overand parallel to the foundation I-beam, and with its web in a horizontalplane, the superstructure I-beam' being of flange to flange widthgreater than that of the foundation I-beam, a plurality 'of upwardlyfacing concave bearings rigidly mountedon the upper side of thefoundation I-beam web, a like plurality of balls,

of radius of curvature less than that of the bearings, resting on saidbearings, and a plurality of downwardly facing concave bearings, ofradius of curvature greater than that of the balls, rigidly mounted onthe lower side of the superstructure I-beam web, and arranged one overand engaged by each of the balls resting on the lower bearings, thebearings and balls being of such vertical thickness relative to thevertical dimensions of the I-beam flanges that the upwardly extendingflanges of the foundation I-beam are overlapped by and received betweenthe downwardly extending flanges of the superstructure I-beam.

4. In an earthquake protected building construction-the combination of afoundation wall, a plurality of upwardly facing concavedbearings rigidlymounted on the upper side of said foundation, a like plurality of balls,of radius of curvature less than that of the bearings, resting on saidbearings, a superstructure wall over said foundation wall, a pluralityof downwardly facing concave bearings, of radius of curvature greaterthan thatof the balls, rigidly mounted on a downwardly facing surface onthe lower portion of said superstructure wall and arranged one over andengaged by each of the balls resting on the concave foundation bearings,and a plurality of tension members connected at their upper and lowerends to the superstructure and foundation walls, respectively.

5. In an earthquake protected building con-' struction, the combinationof a foundation wall, a plurality of upwardly facing concave bearingsrigidly mounted on the upper surface of said foundation, a likeplurality of balls, of radius of curvature less than that of thebearings, resting on said bearings, a superstructure wall over saidfoundation wall, a plurality of downwardly facing concave bearings, ofradius of curvature greater than that of the balls, rigidly mounted on adownwardly facing surface an the lower portion of said superstructurewall and arranged one over and engaged by each of the balls resting onthe concave foundation bearings, a plurality of substantially verticallydisposed hold-down links extending between and to one side of thesuperstructure and foundation walls, an anchor member flexibly linked tothe lower end of said hold-down link and rigidly connected to thefoundation wall, and an anchor member flexibly linked to the upper endof said hold-down link and rigidly connected to the superstructure wall.

faced bearing on the superstructure for the upper side of each ball, andknee braces mounted in interior angles formed by adjacent walls of thesuperstructure.

I. In an earthquake protected building, the combination of adjoiningfoundation walls meeting at an angle, bracing means said walls, asuperstructure above and separate of said foundation, saidsuperstructure including ad'- joining side walls meeting at an angle, aset of balls distributed over the top surface of the foundation andarranged to support said superstructure side walls on the foundation, aconcavely faced bearing on the foundation for the lower side of eachball, a concavely faced bearing on the superstructure for the upper sideof each ball, and bracing means engaging said adjoining superstructureside walls, said bracing means .being adapted to brace said wallsagainst relative movement. 8. In an earthquake protected buildingconstruction, the combination of a foundation structure, a buildingsuperstructure over said foundation structure, a channel beam, arrangedwith its flanges extending in an upward direction, and with its "web ina horizontal plane, mounted on the top of the foundation, acorresponding channel beam, arranged with its flanges extending in adownward direction, and with its web in a horizontal plane, mounted onthe underside of the superstructure directly over the folmdation channelbeam, a plurality of upwardly facing concave bearings rigidly mounted onthe upper side of the foundation channel web, a like plurality of balls,of radius of curvature less than that of the bearings, resting on saidbearings, and a plurality of downwardly facing concave bearings, ofradius of curvature greater than that of theballs, rigidly mounted onthe lower side of the superstructure channel web, and arranged one overand engaged by each of the balls resting on the lower bearings.

9. In an earthquake protected building construction, the combination ofa foundation structure, a building superstructure over said foundationstructure, a channel beam, arranged with ,its flanges extending inan.upward directiomand' with its web in a horizontal plane, mountedonthe top of the foundation, a corresponding, channel beam, arrangedwith its flanges extending in a downward direction, and with its web ina' horizontal plane, mounted on the underside of the superstructuredirectly over the foundation channel beam, the superstructure channelbeing of flange to flange width greater than that of the foundationchannel, a plurality of upwardly facing concave bearings rigidly mountedon the upper side of the foundation channel web, a like plurality-ofballs, of radius of curvature less than that of the bearings, resting onsaid bearings, and a plurality of downwardly facing concave bearings, ofradius of curvature greater than that of the balls, rigidly mounted onthe lower side of the superstructure channel web, and arranged one overand engaged by each of the balls resting on the lower bearings, thebearings and balls being of such vertical thickness relative to thevertical dimensions of the channel flanges that the upwardly extendingflanges of the foundation channel are overlapped by and received betweenthe downwardly extending flanges of the superstructure channel.

GIUSEPPE CAVAGLIERI.

